Objectives: (1) to clarify and extend our finding of differences in autonomic nervous system (ANS) that distinguish among four negative emotions (fear, anger, disgust and sadness) and between these negative emotions and the emotions of happiness and surprise. (2) to determine whether such patterns of ANS activity are emotion-specific regardless of how the emotion was brought forth, or vary with the emotion elicitor. (3) to learn how the intensity of an emotion and blends of emotion are registered in ANS activity. (4) to show that it is possible to have differentiated emotional experience (in ANS and subjective report) with no facial activity, by examining patients with Mobius syndrome. (5) to illuminate what mechanisms are involved in voluntary facial actions generating differentiated ANS activity and subjective emotional experience. (6) to examine ANS activity where two emotions are called forth simultaneously in a blend. (7) to examine individual differences in expressive and autonomic activity. Health relevance: Study of emotion blends may show that it is when emotions occur simultaneously that people become confused about how they feel. Learning what happens to physiology when emotions with quite different physiological patterns occur simultaneously may be relevant to understanding when emotions can have adverse health consequences. Determining whether voluntary efforts to generate emotion can terminate or attenuate involuntary emotions will begin to suggest whether our techniques for self-generation of emotion have any possible therapeutic value.